3GPP Long Term Evolution, LTE, is the fourth-generation mobile communication technologies standard developed within the 3rd Generation Partnership Project, 3GPP, to improve the Universal Mobile Telecommunication System, UMTS, standard to cope with future requirements in terms of improved services such as higher data rates, improved efficiency, and lowered costs. The Universal Terrestrial Radio Access Network, UTRAN, is the radio access network of a UMTS and Evolved UTRAN, E-UTRAN, is the radio access network of an LTE system. In an UTRAN and an E-UTRAN, a User Equipment, UE or wireless device, is wirelessly connected to a Radio Base Station, RBS, commonly referred to as a NodeB, NB, in UMTS, and as an evolved NodeB, eNodeB or eNB, in LTE. An RBS is a general term for a radio network node capable of transmitting radio signals to a UE and receiving signals transmitted by a UE.
Traditional transport services e.g. leased lines or Virtual Private Networks, VPNs, are used for transport in the Radio Access Network, RAN. These transport services are very expensive in particular for high bandwidth data services. Internet transport services are much cheaper than traditional transport services. Using Internet for transport services in the RAN will lower the transport cost dramatically. An Internet transport service cost can be a fraction of the cost of a traditional leased lines and VPN services. There is a clear trend in Enterprise networking to use Internet transport services for transport and Mobile Network Operators are starting to put forward this requirement also for the RAN.
Using Internet as transport will expose the connected equipment in the RAN to various attack threats e.g. hackers, viruses, bot-nets, trojans etc. Hackers will search connected devices in the RAN for vulnerability. An attack can start with a port-scan of an IP address on the equipment in the RAN to figure out open ports and then try to connect to the equipment in order to intrude the RAN-equipment.
A counter measurement used in transport networks today are Intrusion Detection System, IDS, and Intrusion Prevention System, IPS.
An IDS is a device or software application that monitors network or system activities for malicious activities or policy violations and produces reports to a management station. There are different types of IDS, but they all are designed to detect suspicious traffic in different ways. An IDS is primarily focused on identifying possible incidents, logging information about them, and reporting attempts.
An IPS can respond to a detected threat by attempting to prevent it from succeeding. IPS use several techniques to counter the attack e.g. dropping packets from attacker, changing the security environment (e.g. reconfiguring a firewall) or making changes in attacker's packet headers.
The IPS functionality tries to stop or limit the impact of a network attack by working in-line with the real network traffic, to be able to take actions to actively prevent or block intrusions or denial of services attacks that are detected. These actions are in the form of activating filters to drop/block IP packets, resetting the connection, reassemble fragmented IP packet etc.
One problem when a radio access network and core network is connected to an unsecure network like the Internet is that the IPS has no knowledge of the impact an Internet attack will have on the RAN and the services delivered to the end-users connected to the RAN.
The IPS can take an action to drop traffic from an Internet attacker, but at the same time the usable capacity for e.g. a RBS in the RAN will be limited. This will result in that the RBS in the RAN will still try to serve equal amount of UEs as if the RBS had expected full capacity on the Internet transport services. This will result in very limited end-user performance and Quality of Experience, QoE. It is only when the RBS has so low/limited capacity that the radio signalling can't get through that the RBS will understand that the RBS must be taken out of service. The RBS can't detect that end-user traffic between a S/PGW in the CN and the RBS is dropped due to an Internet attack, even if a significant part of the packets are dropped. The impact will only be seen by the UE as a very limited connection/service.
There is therefore a need for an improved solution for handling Internet attacks in a RAN using Internet transport, which solution solves or at least mitigates at least one of the above mentioned problems.